THE
CUSTOM TUNED DYNOMAX CHASSIS
Guest Post by Carolyn
Gsell, former Customer Care Specialist Extraordinaire with the Country Coach, LLC Sales Dept.
“…Nobody tests a motorhome, and in
particular the chassis, the way it was done at Country Coach.”
I was thinking about that this week
as some customers were talking in the customer lounge at Premier RV Services in
Junction City where I work, and I remembered this great article by my friend
Carolyn Gsell authored back when Country Coach LLC was building coaches…It’s still a wonderful look into that DynoMax chassis upon which
some of the World’s Finest Motorcoaches were founded….
The foundation of a Country Coach motorhome (with the
exception of Prevost Conversions) was the DynoMax Chassis. A look at the steel
structure is telling. The massive framework of welded tubular steel with 8 x 3
frame rails will withstand almost any brute force that it comes up against. But
ultimately what owners of a Country Coach experience is the incredible ride and handling attributes
when driving down the highway, and its nimbleness when faced with tight
turning areas in campgrounds and in-town driving. So how did the engineers at
Country Coach marry ruggedness with driveability? The surface answer goes back
to the company’s basic engineering principle – Safety, Function, & Design.
…The Chassis designers went to work to develop a steel structure of unsurpassed strength and durability. Utilizing high strength tubular steel they
welded together to create the steel cage (the basement, if you will). They next
welded the cage to massive 3” x 8” tubular steel frame rails. With this
structure in place, Country Coach could utilize the highest horsepower engines
on a chassis that could absorb the sheer power and torque that such big engines
generate. This meant they chose not to use C channel steel (imagine tubular
steel that is missing its widest side, hence the “C” shape). They could have
employed an easier, quicker process of bolting the steel together, rather than
fusing the steel with high grade welds… but they didn’t. A fiberglass coach has
the roof, walls and floors connected somehow to the chassis. CC engineers had
to figure a way to integrate these separate house components with the chassis
so that it could be fully integrated for the coach to safely travel the road.
Chassis engineers built cross bracing into the steel cage structure, properly
spaced openings for storage and other components, evenly distributed weight of
components, and designed a laminated floor for the house that fully integrated
into the chassis structure. The result was a semi-monocoque design where the
house came together with the chassis for a motorhome of superior strength and
stability.
Another critical aspect of the DynoMax design is the suspension
system. Engineers determined that the Independent Front Suspension
(IFS) was a crucial component contributing to the smooth drive of a motorhome.
From this standpoint, safety and comfort points stack up with the use of
DynoMax’s Independent Front Suspension with its double wish-bone construction.
The IFS design allows one front wheel to react to an impact independent of the
other front wheel; and a major reduction in road stress achieved…The other
feature of the suspension was Country Coach’s approach to airbag size and
positioning. Country Coach recognized that if they mounted the airbags farther
apart, as in outboard mounted airbags, your coach could have the feel of a race
car suspension. The DynoMax difference is to mount large volume air bags
inboard of the wheels. The size and positioning, in combination with the weight
of the coach, provides the luxurious ride that owners love in their Country
Coach. Further stabilizing the ride, Country Coach engineers supplied plenty of
on-demand air from strategically placed air canisters to the air bags, so that
as your coach makes its way around corners and deep curves, the instantaneous
delivery of air to one side makes up for movement on the opposing side. Now add
the IPD anti-sway bar and all factors add up to one of the best driving
motorcoaches ever built.
DynoMax chassis
elements that contribute to your personal safety and comfort are numerous.
Note the massive “firewall”,
the plate of steel to which your brake and accelerator pedals are mounted, and
which also in conjunction with fiberglass dash and fiberglass front cap creates
a barrier between you, sitting in the driver and copilot seat, and the world
beyond your front bumper. Notice the wide entry area between the firewall and your
co-pilot’s seat. This distance, in combination with the steel firewall
and steel cage structure below, adds monumental protection in the unlikelyevent
of a head-on collision. One testimonial to
this, back in 2003 a Country Coach driver was delivering a Country Coach to an
industry show. He found himself in the midst of a sandstorm. With his
visibility obscured, he ran into a semi truck while traveling at 40 mph. The
driver walked away from that accident uninjured and the coach was returned to
Country Coach for repairs. Now that is a great testament to safety!
Once the entire frame with axle
assemblies was welded together, the chassis was taken to a special paint booth
where rust
inhibitive paint was applied around every bit of steel that makes up
the structure. While the process is important to protecting the steel, Country
Coach took this one step further. Most chassis manufacturers utilize an
assembly line approach, with the paint application being the final step. At
Country Coach, builders took the time to pull the frame out of its station,
take it to the paint booth, and then move it into another short assembly line
where the drive train was installed. Open up the engine access doors of a
competitor’s product and you may see paint overspray on the engine,
transmission or hose lines. By taking the time to paint the frame prior to
installing drive train components, it’s unlikely you’d ever see this on a
Country Coach.
Note: As a special note
regarding the special black rust inhibitor applied to the chassis, sheet metal
and angled iron used at that time was not available from the suppliers with the
zinc oxide process. So these areas are more susceptible to rust (wheel wells,
battery bay, propane bay, service center). A preventative care step is to give
a good thorough power washing of the coach undercarriage after each trip to
help prevent rusting in those susceptible areas. Now...back to the chassis
info.
After the chassis frame is painted, it was moved to the
drive train assembly area. Installers and assemblers with engine/transmission
hoists installed the power plant that makes your coach move down the road. When
it comes to engines and transmissions, Country Coach utilized only the most
powerful power plants on the road. The line-up of heavy duty
engine/transmission combinations boasts horsepower and torque curves that gave
each motorhome the boost needed for climbing hills or navigating our nation’s
superhighways.
While the engine installation was in progress, the wire
harnesses, brake fluid lines, heater hoses and air lines were laid down in the
channel between the two main frame rails. To prevent chaffing of hoses and
conduit against metal, strips of neoprene line the rails upon which the wires
and hoses rest. This procedure greatly reduces the amount of friction and assures
the integrity of the lines. So that your bays look clean and attractive, the
lines are covered with removable cargo panels so that they are accessible for
any possible trouble shooting or repairs. Batteries on convenient pull-out
trays, filters, air tanks, brake and accelerator pedals – basically everything
necessary to the function and maintenance of the chassis, are installed and
hooked up at this time. The initial set up for the plumbing bay was also
started in this area. The insulated floor was installed, and the holding tanks
were mounted in place.
And speaking of heavy duty, weight distribution plays a key
roll in how comfortable you feel when driving your coach, and also plays into
safety. An unbalanced load would make driving a motorhome challenging at best.
Country Coach engineers paid close attention to creating the right balance at
the basement level of your coach, through careful placement of holding tanks,
the fuel tank and other chassis components. The fuel tank is located directly
rearward of the front wheels, and spanning curbside to driver side, with the
bonus convenience of allowing diesel fuel to be pumped on either side of the
coach in most Country Coach chassis designs. Just forward of your drive wheels
is one large bay for all the fresh, black and gray holding tanks – again,
weight balanced side to side. With the lower weight distributed in accordance
with axle carrying capacities, engineers designed the bay storage in between
the front and rear so that you, the owner, can load up your provisions knowing
that the proper weight balance has already been 98% achieved by the inherent
design and placement of the chassis bays.
DynoMax chassis are rated for towing. With high tow weight ratings, owners have a wide range of options for what they may choose
to tow, without the limitations other RV’s put on their towing capacities.
CC engineers went the extra mile in this chassis design by
adding a layer of neoprene, which acts as a vibration dampening material, on the underside of the engine deck floor, with
continuous strips of this same material being applied forward of this area on
the upper side of all the chassis steel rails. Most other RV manufacturers
choose not to take the time to add this material. It is another of the
differences that you’ll find in the Country Coach build process that makes
Country Coach stand out ahead of every other motorcoach in its class.
These chassis features add up to create the luxurious smooth
ride that one experiences driving a Country Coach. One testimonial
on that smooth ride was shared in a 2005 issue of CC Destinations. An owner of
a 2002 Affinity once rested a pocket knife curved side down on the belt molding
of the driver side slide room. Not remembering he had left it there, he and his
wife departed from the campground complete with speed bumps, navigated a steep
grade and large chuckhole, and then traveled another 128 miles where they
stopped at another RV park. The next day, the coach owner found his knife still
sitting in the same exact location where he had left it (that story, “The
Little Kershaw Knife that Could”, appeared on page 64, Autumn 2005 Destinations
Magazine).
Ask a manufacturer of a motorcoach how they test their
chassis and they may describe the initial design and testing when the chassis
model was first designed, or describe the road test performed on their newly
manufactured units. Nobody tests a motorhome, and in particular the chassis,
the way it was done at Country Coach. Before each chassis was put into
production, it was taken to the Dynocenter, where the chassis was chained down
and the engine hooked up to a Dynomometer. Before the Dyno Test began, quality
auditors closely inspected welds, wiring, hose connections and bolt torques to
insure that every chassis component was correctly assembled. Once done, with
the use of 7000 lbs of water delivering force to steel drums that allowed the
drive wheels to work against a load, the chassis was “started” from an enclosed
room overlooking the test area. By putting the drive train through the paces,
Country Coach evaluated the data to make sure horsepower output of the engine
matched the manufacturer’s specifications. If anything came up, it was
immediately corrected and if necessary, the chassis was “dyno’d” again. The
Dyno program was in place from 2001 until the company closed in 2009. The rigorous Dyno process helped ensure
quality and integrity of your DynoMax chassis.
These days are exciting times too....as Ron Lee and Country Coach Corporation are at work on a new generation of Country Coach motorcoaches. The first one is being built this year. Pop over to www.countrycoach.com to learn more about that.
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